Prior art seat support assemblies for use in supporting truck seats and other vehicle seats have included structures with various means for controlling the vertical movement of the vehicle seat. One prior art seat support includes a frame which is vertically adjusted by two parallel links each having teeth and an independent pivoting lever which fits into the teeth in the links to control the height of the seat. These seat supports require a substantial vertical space when in the collapsed position and can be used only if there is sufficient clearance between the floor of the vehicle and the bottom of the supported seat.
Another prior art seat support assembly includes an upper housing which is vertically adjusted by a pair of scissor links or parallel links which are raised by tension springs. The scissor links or parallel links are attached to the upper housing and to a height adjustment knob such that the turning of the height adjustment knob will engage the scissor links and raise the seat. This seat support assembly also requires substantial vertical space between the floor of the vehicle and the bottom of the seat.